a) out of 10 people, 90% will be right handed (or 0.9)
b) multiply the probability of getting one right handed person by itself
0.9*0.9= 0.81 or 81%
c) the probability of getting all left handed people is
0.10^10 = 0.00000001 (just as in previously step)
therefore, 1 - 0.00000001 = 0.99999999 is the probability of getting at least one person right handed